Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Four proteins, which have been designated A, B, C and D, have been purified from human parotid saliva. These proteins are the major constituents of parotid saliva which migrate rapidly to the anode in polyacrylamide electrophoresis at pH9.5. Gel filtration and polyacrylamide electrophoresis were employed in the purification procedures. After purification all four preparations were tested for homogeneity by electrophoresis at pH2.8 and 9.5, by isoelectric focusing in the pH range 3-10, by immunodiffusion, and by sedimentation in the analytical ultracentrifuge. None of the proteins showed significant activity in assays for amylase, acid and alkaline phosphatase, protease, lysozyme, ribonuclease, peroxidase, beta-glucuronidase, beta-galactosidase, iron-binding activity and esterase. No cross-reactions were detected with antisera specific for lactoferrin and 15 serum proteins. All four proteins were rich in glutamic acid, proline and glycine and were lacking completely the sulphur-containing amino acids. Proteins A and C contained no threonine or tyrosine. Carbohydrate could be demonstrated only in protein A at a concentration of 4% of the total protein.
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PMID:Purification and partial characterization of four proteins from human parotid saliva. 500 93

Intravenous inoculation of rabbits with spores of Absidia corymbifera strain V.73/8 produced acute phycomycosis and death within 2 to 10 days. Cultural and microscopical examination showed that fungal infection was widespread and involved most organ systems but with particularly extensive lesions developing in the kidneys. The progress of the infection was associated with a raised leucocyte count, an increasing erythrocyte sedimentation rate and significant changes in serum biochemistry. The latter included a decrease in serum iron, zinc, alkaline phosphatase and gamma-glutamyl transpeptidase concentrations but an increase in the synthesis of acute phase proteins and in the phenylalanine:tyrosine ratio and in serum concentrations of copper, magnesium, potassium, lactate dehydrogenase and triglycerides. The serum urea concentration increased substantially during the terminal phase of infection.
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PMID:Biochemical and pathological changes in experimental phycomycosis. 613 59

An autoantibody against mid-C-regional, possibly mid-regional, parathyroid hormone was detected in the plasma of a patient with terminal renal insufficiency who was on intermittent haemodialysis. 43-68(Tyr)hPTH and 42-55(Tyr)hPTH were selectively bound by his IgG fraction. 43-68(Tyr)hPTH had the highest affinity for the autoantibody; intact parathyroid hormone did not displace radiolabelled 42-55(Tyr)hPTH or 43-68(Tyr)hPTH. As concentrations of circulating antibodies against mid-C/mid-regional parathyroid hormone fell rises in intact and mid-C-regional parathyroid hormone levels and in alkaline phosphatase activity were observed. This autoantibody directed against the middle portion of the parathyroid hormone molecule seemed to have some protective properties against the osteoblast-stimulating activity of the hormone, implying that the mid-C-region or middle region of the molecule has some biological importance.
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PMID:Autoantibodies against parathyroid hormone in a patient with terminal renal insufficiency. 614 35

A relationship between the second phase of the nucleolar activity and the variations which the yolk globules undergo in their staining affinities and in their chemical constitution has been found in growing oocytes o Murex trunculus. The results obtained enable us to recognize that the different staining affinities among the initial intermediate and definitive yolk granules correlate with the variations in their chemical constitution. The variations are due to the lack of proteins with disulfide groups, tryptophan, indolic and phenolic substances and tyrosine in the initial yolk globules, substances which, on the other hand, are found in both intermediate and final globules. Furthermore, the final globules are lacking in lipids. The presence of both acid and alkaline phosphatase activities is limited mostly to the initial yolk globules. It was possible to deduce from the chemical constitution in the nucleus of the oocytes under examination that the phase in which the nucleous modifies its content of chemical substances and when the transformation in the chemical constitution of the yolk globules occurs, is not coincidental. Both of these phenomena occur when vitellogenesis is advances although the nucleus undergoes vacuolization through out the time in which previtellogenesis passes to vitellogenesis. That the presence of the hydrolytic enzymes is correlated with nucleolar activity and that their probable role is connected with the yolk transformation and subsequent reconstruction is discussed.
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PMID:Structural and cytochemical features of the yolk globules and of the nucleolus in the growing oocytes of the mollusc Murex trunculus L. 617 5

The acid and base stability of the phosphoryl bond of phosphotyrosine (Tyr-P) was studied using conditions for rapid and complete hydrolysis of protein peptide bonds. A method was developed for the quantification of Tyr-P in proteins using rapid base hydrolysis and an amino acid analyzer equipped with a fluorometric detection system. The recovery of [32P]Tyr-P from base digests of radiolabeled samples of phosphotyrosyl glutamine synthetase, transforming protein of Rous sarcoma virus, casein, and rabbit anti-sarcoma IgG was 80 +/- 2%. Phosphotyrosine could not be detected in several commercial histone samples, but Tyr-P was detected in phosvitin samples. The putative Tyr-P from the phosvitin hydrolysate was separated from normal amino acids by Dowex 50-H+ chromatography. Treatment of the partially purified Tyr-P with bacterial alkaline phosphatase produced tyrosine in near equivalent quantities to the measured level of Tyr-P. These results show that basic hydrolysis of phosphotyrosyl proteins yields Tyr-P in constant and good yields which can be quantified in amounts greater than or equal to 100 pmol or radiochemically detected in smaller amounts with an amino acid analyzer.
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PMID:Phosphotyrosine in proteins. Stability and quantification. 617 34

Thirteen monoclonal antibodies to ppp(A2'p5')nA oligonucleotides have been produced by fusing Y3 myeloma cells with spleen cells of rat hyperimmunized with A2'p5'A succinyl albumin as immunogen. 125I-labeled A2'p5'A succinyl tyrosine methyl ester was used as a labeled probe. Antibodies were detected by their ability to bind the labeled analog and were selected for their affinity for A2'p5'A. There were no significant differences between the properties of the monoclonal antibodies and of the antiserum. They discriminated between 2'-5' and 3'-5' phosphodiester bonds: they crossreacted poorly with (A3'p5')2A (crossreactivity ratio, greater than 10(4)) and even less with ATP an adenosine (crossreactivity ratio, greater than (6)). The affinity was high (Kd = 6 x 10(-12) M) for succinyl A2'p5'A, which is the best ligand, and also high for A2'p5'A (crossreactivity ratio, 3) and (A2'p5')2A, (A2'p5')3A, and (As'p5')4A (crossreactivity ratio, 7.5). The binding to triphosphorylated isomers, ppp(A2'p5)nA, was affected by the presence of the triphosphate groups, and the affinity increased as the length of the isomer increased (crossreactivity ratio, 10,000 for n = 1 to 200 for n = 4). Thermodynamic analysis of these data demonstrated that, in dephosphorylated isomers, the binding site of highest affinity was located at the 5'-OH end of the molecule whereas in phosphorylated isomers, the favorable binding sites were in the middle and at the 2'-OH end of the chain. Use of monoclonal antibodies of such a specificity together with the 125I-labeled 2-5A analog allows quantification of (A2'p5')nA directly and of ppp(A2'p5')nA after removal of the terminal phosphates by alkaline phosphatase treatment.
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PMID:Monoclonal antibodies to 5'-triphospho-(2'-5')adenyladenosine oligonucleotides. 618 14

To determine the equilibrium constant of the reaction between ATP and protein-bound tyrosine we used as catalyst the highly purified Rous sarcoma src gene transcript. J. M. Sturtevant had earlier found (personal communication) that free tyrosine O-phosphate, upon hydrolysis with alkaline phosphatase in a calorimeter (37 degrees C, pH 9), yielded a delta H degrees of -2.8 kcal/mol (1 kcal = 4.18 kJ), less than half of that found in ATP hydrolysis. Experience with protein-bound serine phosphate (in phosvitin) had shown it to be energy rich [Rabinowitz, M. & Lipmann, F. (1960) J. Biol. Chem. 235, 1043-1050]. We wondered if the same is true for tyrosine phosphate when it is protein bound. From the equilibrium constant of 2.62 (at pH 6.5 and 5 mM Mg2+), we calculate a delta G degrees' of -9.48 kcal/mol for hydrolysis of protein-bound tyrosine phosphate, assuming an approximate delta G degrees' of -10 kcal/mol for hydrolysis of ATP. The experiments show that protein-bound tyrosine phosphate is energy rich, like serine phosphate in phosvitin.
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PMID:Reversal of Rous sarcoma-specific immunoglobulin phosphorylation on tyrosine (ADP as phosphate acceptor) catalyzed by the src gene kinase. 618 57

The synthetic phosphohexapeptides Arg-Arg-Ala-Thr(35P)-Val-Ala and Arg-Arg-Ala-Ser(32P)-Val-Ala, phosphorylated by the cAMP-dependent protein kinase and differing only in the nature of the phosphorylated residue, have been used as substrates of a partially purified rat liver protein phosphatase-T, distinct from the multifunctional protein phosphatase-1. While the phosphothreonyl hexapeptide is readily dephosphorylated (exhibiting a Km = 15 microM), the phosphoseryl one is almost unaffected. Such a behavior is not shared by protein phosphatase-1, calf intestine alkaline phosphatase, and potato acid phosphatase, all of which are more active on the phosphoseryl hexapeptide. The NH2-terminal basic residues critical for cAMP-dependent phosphorylation are not required in the dephosphorylation reaction, as both Arg can be removed without impairing the efficiency of protein phosphatase-T toward the phosphothreonyl peptide. On the other hand, the replacement of 2 Pro for the Ala and Val flanking Thr(32P), to give a new phosphohexapeptide reproducing the phosphorylated site of protein phosphatase inhibitor-1, prevents the protein phosphatase-T activity. Moreover, IgG heavy chain 32P labeled in tyrosine is not affected by protein phosphatase-T, while it is dephosphorylated by alkaline phosphatase. These results would indicate that protein phosphatase(s)-T represent a distinct class of protein phosphatases specifically involved in the dephosphorylation of phosphothreonyl residues fulfilling definite structural requirements.
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PMID:Dephosphorylation of synthetic phosphopeptides by protein phosphatase-T, a phosphothreonyl protein phosphatase. 628 35

A small fraction of polyoma virus middle-sized tumor (T) antigen is phosphorylated in vivo, resulting in a small amount of phosphotyrosine and phosphothreonine and significantly larger amounts of phosphoserine. When infected cells are separated into nuclear, plasma membrane, and low-speed supernatant fractions, 80-95% of in vivo-phosphorylated middle-sized T antigen is localized to the plasma membrane fraction, while 25-50% of [35S]methionine-labeled middle-sized T antigen is found in the nuclear fraction and the same amount is found in the plasma membrane fraction. Immunoprecipitated T antigens contain a protein kinase activity that phosphorylates middle-sized T antigen at tyrosine residues. Eighty to 90% of this activity is located in the plasma membrane fraction. When immunoprecipitated T antigens are treated with alkaline phosphatase, middle-sized T antigen-phosphorylating activity decreases as 32PO4 is lost from in vivo 32P-labeled middle-sized T antigen. The possibility that in vivo-phosphorylated middle-sized T antigen located in the plasma membrane is an active tyrosine-specific kinase is discussed.
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PMID:Differential subcellular localization of in vivo-phosphorylated and nonphosphorylated middle-sized tumor antigen of polyoma virus and its relationship to middle-sized tumor antigen phosphorylating activity in vitro. 629 53

Possible physiological factors that might control the extent of phosphorylation of ACTH-related peptides in the rat pituitary were investigated both in vivo and with cultured anterior or neurointermediate pituitary cells. Phosphorylated and nonphosphorylated forms of ACTH and corticotropin-like intermediate lobe peptide [CLIP or ACTH(18-39)] were separated by isoelectric focusing or high performance liquid chromatography and quantified by immunoassay. Radiolabeled ACTH- or CLIP-related peptides from cultured pituitary cells incubated in [3H]tyrosine were isolated by immunoprecipitation or immunoadsorption, fractionated as above, and detected by liquid scintillation counting. Both in the animal and in culture, the extent of phosphorylation of anterior pituitary cellular ACTH did not vary when the release of ACTH was stimulated (by metyrapone treatment, corticotropin-releasing factor, or cAMP) or inhibited (by dexamethasone). Long term cultures of rat anterior pituitary cells continued to phosphorylate ACTH in both serum-containing and serum-free medium; the extent of phosphorylation of ACTH rose from about 55% in vivo to 80% within 1 week in culture. By comparison, the extent of phosphorylation of intermediate pituitary CLIP decreased from about 75% in vivo to about 40-50% in culture. The extent of phosphorylation of the ACTH and CLIP secreted by primary pituitary cultures simply reflected the extent of phosphorylation of ACTH and CLIP in the cells, in both basal and stimulated states. Human ACTH(1-39) contains the same amino acid sequence that is phosphorylated in rat and mouse ACTH(1-39). Based on isoelectric focusing and high performance liquid chromatography of the tryptic peptides of human ACTH (with and without alkaline phosphatase treatment), about one third of the ACTH in the human pituitary is phosphorylated.
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PMID:Phosphorylation of rat and human adrenocorticotropin-related peptides: physiological regulation and studies of secretion. 630 52


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